The symbols on the bar are used to identify certain socket outlet functions:
Clock symbol: This socket outlet is controlled via switching logic - depending on the model, it can be switched via a main switch or be part of a main-follow function, for example.
Earthing symbol (⏚): This symbol indicates that the power strip has integrated overvoltage protection.
For overvoltage protection:
Even if only one socket outlet is marked with the earthing symbol, the integrated surge protection basically affects all socket outlets on the power strip simultaneously. The protective circuit is installed centrally and affects the entire power strip.